Register

Database Lossless Join

768 views

1 Answer

1 1 vote
  A B C D E G
R1 X X        
R2   X X      
R3 X X   X X  
R4         X X

Applying functional dependencies E-> G, we can put X in column G of R3, but we cannot get any row with all X.

So D1 is lossy.

  A B C D E G
R1 X X X      
R2 X   X X X  
R3 X     X   X

Applying functional dependencies, AC-> B, we can put X in B. Still no row with all X.

So lossy.

Hence option D.

Voting & Accepting an answer helps improve the community
Answer:
← Previous · WIFI madeeasyNext → · MadeEasy Subject Tes...
← Previous in category · ER ModelNext in category → · MadeEasy Subject Tes...
Position:
Show:

Related questions

1 1 vote
1 answers 1 answer
1.7k
1.7k views
amitqy asked Apr 7, 2019
1,690 views
made easy test series - lossless join and dependency preserving
How is A answer?
1 1 vote
2 2 answers
1.1k
1.1k views
Balaji Jegan asked Jul 9, 2018
1,139 views
Lossless Join and Dependency Preservation
Consider R(B->D, C->B, D->A)Consider the following 2 decompositions : R1(ABC) and R2(CD).Whether this is a lossless decomposition?Whether this is a lossless decomposition...
2 2 votes
1 1 answer
2.2k
2.2k views
Mk Utkarsh asked Jan 12, 2018
2,215 views
Lossless join
1 1 vote
2 2 answers
1.2k
1.2k views
Tuhin Dutta asked Dec 8, 2017
1,235 views
lossless join
$R(X,Y,Z,W) is\ decomposed\ into \\ R_1(X,Y)\\ R_2(Y,Z)\\ R_3(Y,W).\\The\ FDs\ are\ :\\ X - Y,\\ Z->Y,\\ Y->W \\ Find\ whether\ the\ decomposition\ is\ lossless\ or\ ...